• Title/Summary/Keyword: speed limits

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Benefit of Sag Vertical Curves for Rail Transit Routes (철도대중교통 곡형 종단곡선의 편익)

  • 김동령
    • Proceedings of the KOR-KST Conference
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    • 1996.06a
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    • pp.95-128
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    • 1996
  • Dipped track profiles between rail transit stations can significantly reduce propulsive energy, braking energy and travel times. This work quantifies their potential benefits for circumstances reflected in various values for dips, speed and acceleration limits, station spacings, and available power. A deterministic simulation model has been developed to precisely estimate train motions and performance using basic equations for kinematics, resistance, power and braking. For a dip of 1% of station spacing, in which gradients never exceed 4%, our results show savings (compared with level tracks) exceeding 9% for propulsive energy, 15% for braking energy and 5% for travel time between stations.

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Evaluation of Static Strength and Fatigue Strength for Bogie of a Korea High Speed Train Including Eddy Current Brake System (와전류 제동장치를 포함한 한국형 고속전철 대차의 정적강도 및 피로강도 평가)

  • 노규석;이상록;강재윤
    • Proceedings of the KSR Conference
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    • 2001.10a
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    • pp.267-272
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    • 2001
  • A FEM-based analytical approach was used to evaluate the static strength and the fatigue strength of a KHST bogie including eddy current brake system. Calculation was carried out in the fields of linearity and small deformation. The yield strengths were used as criteria for evaluating the static strength and the fatigue limits were used as criteria for evaluating the fatigue strength. The analysis results show that there is not any location that exceeds the allowable criteria.

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A Primary Study on the Location and Size of Railway Station Facilities (철도 역시설의 입지와 규모에 관한 기초 연구)

  • 문대섭;이경철;정병현
    • Proceedings of the KSR Conference
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    • 2002.05a
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    • pp.116-121
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    • 2002
  • This primary study has some bounds md limits owing to the descriptive reviews but not detailed analyses. However, 1 tried to do the comparative analyses and case studies about location and size of rail station for future efficient use of spatial structure. Therefore, I reviewed the location of railway station and some design standards of railway station facilities by type (high speed rail, conventional rail and urban rail), and also, suggested future direction for rail station as the core of city development relating with urban structures and human settlement system reformation.

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Molecular Breeding for Plant Disease Resistance : Prospects and Problems

  • Park, Hyo-Guen
    • The Plant Pathology Journal
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    • v.17 no.1
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    • pp.1-8
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    • 2001
  • The technique of plant transformation has started to show off its great power in the area of plant breeding by commercially successful introduction of transgenic varieties such as herbicide tolerant soybean and insect resistant corn in USA with an unimaginable speed. However, in contrast with the great success in the commercialization of herbicide tolerance and insect resistance, the transformation works on disease resistance has not yet reached the stage of full commercialization. This review surveys the current status of molecular breeding for plant disease resistance and their limits and problems. Some novel ideas and approaches in molecular breeding for disease resistance are introduced.

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A Comparative Study on the Traffic Effects of Speed Limit Reduction on the Urban and Provincial Roads (제한속도 하향에 따른 도시부 도로와 지방부 도로의 교통영향 비교 분석)

  • Yoon, Young-Min
    • The Journal of the Korea Contents Association
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    • v.20 no.9
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    • pp.430-438
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    • 2020
  • Many local governments are reducing speed limits according to the "Safe Speed 5030" policy implemented by the government to reduce traffic accident deaths. In the urban road sections in many metropolitan cities where speed limit reduction is applied as a pilot project, the decrease effect of the traffic accident number and death count is shown; however, no study of the effect analysis on the road sections of medium and small cities (basic local government unit) is found. Therefore, this study investigated the travel speed, number of traffic accidents, and death count before and after the implementation of speed limit reduction, targeting some urban road sections in Pyeongtaek city and some provincial road sections in Icheon city among basic local governments, namely among medium and small cities in Seoul Metropolitan Area.

A Study on the Damaging Distance and the Explosion Effect by the LPG Release (LPG 누출시 피해거리 및 폭발영향에 관한 연구)

  • 이경덕;신창섭
    • Journal of the Korean Society of Safety
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    • v.14 no.2
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    • pp.109-115
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    • 1999
  • The release of gas from the LPG storage tank by the rupture or leakage can occure explosion and this causes serious damage to people and structures. In this study, the explosion effect and damaging distance were measured for the LPG cloud explosion to perform the quantitative risk assessment for the PSM, and the effective parameters on the explosion were found. The gas dispersion and mass contaminant in the explosion limits were calculated by using DEGADIS, and it was converted to TNT equivalency and damaging distance. As a result, the wind speed was the most effective parameter on the diffusion rate and TNT equivalency, and the damaging distance were increased with decrease of wind speed and surface roughness.

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A Study on the Printability according to the Ink and Damping Water Change in Newspaper Printing (신문윤전기에서 잉크와 습수량 변화에 따른 인쇄적성에 관한 연구)

  • Lee, Man-Gyo;Ha, Young-Baeck;Youn, Jong-Tae
    • Journal of the Korean Graphic Arts Communication Society
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    • v.23 no.1
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    • pp.13-25
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    • 2005
  • In order to technical analysis of the Newspaper printing press, the printability such as, dot gain, contrast and printing density change according to the amount of ink and damping water feeding were experimented. t도 Printability assurance in printing aims at a correct and constant color reproduction throughout the whole print-run. And the checked values were checked from densitometer and colorimeter instead of conventional subjective method. In this research, we could propose the range of driving in printing of domestic Newspaper printing press as well as the limits of ink feed speed and damping water feed speed.

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A Implementation of Simple Convolution Decoder Using a Temporal Neural Networks

  • Chung, Hee-Tae;Kim, Kyung-Hun
    • Journal of information and communication convergence engineering
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    • v.1 no.4
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    • pp.177-182
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    • 2003
  • Conventional multilayer feedforward artificial neural networks are very effective in dealing with spatial problems. To deal with problems with time dependency, some kinds of memory have to be built in the processing algorithm. In this paper we show how the newly proposed Serial Input Neuron (SIN) convolutional decoders can be derived. As an example, we derive the SIN decoder for rate code with constraint length 3. The SIN is tested in Gaussian channel and the results are compared to the results of the optimal Viterbi decoder. A SIN approach to decode convolutional codes is presented. No supervision is required. The decoder lends itself to pleasing implementations in hardware and processing codes with high speed in a time. However, the speed of the current circuits may set limits to the codes used. With increasing speeds of the circuits in the future, the proposed technique may become a tempting choice for decoding convolutional coding with long constraint lengths.

Trends in Neuromorphic Photonics Technology (뉴로모픽 포토닉스 기술 동향)

  • Kwon, Y.H.;Kim, K.S.;Baek, Y.S.
    • Electronics and Telecommunications Trends
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    • v.35 no.4
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    • pp.34-41
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    • 2020
  • The existing Von Neumann architecture places limits to data processing in AI, a booming technology. To address this issue, research is being conducted on computing architectures and artificial neural networks that simulate neurons and synapses, which are the hardware of the human brain. With high-speed, high-throughput data communication infrastructures, photonic solutions today are a mature industrial reality. In particular, due to the recent outstanding achievements of artificial neural networks, there is considerable interest in improving their speed and energy efficiency by exploiting photonic-based neuromorphic hardware instead of electronic-based hardware. This paper covers recent photonic neuromorphic studies and a classification of existing solutions (categorized into multilayer perceptrons, convolutional neural networks, spiking neural networks, and reservoir computing).

The Study on the Rules for Efficiency of Train Operation (열차운행효율화를 위한 운전관계 사규에 대한 연구)

  • Oh, Min-Seok;Kim, Ho-Soon;Jeong, Do-Won
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.823-829
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    • 2010
  • Railway is facing a new era by the remarkable technology-intensive development of railways in the rolling stock and track, trains and infrastructure facilities. But the relevant provisions of the regulations for the various driving speed limit accept most of the past rules and it is desperately needed to realize the efficiency of the train operation. In addition, because the rules that drive too many treats of redundancy(the same information is duplicated in the other company policy provisions), they can cause confusion among employees, and also because of the contents of the detailed provisions dealing with almost same regulations, they can cause probable failure and big accident. In this study, the relevant provisions of the current rules are analyzed and overcome problems to improve efficiency and duplicated contents of relevant provisions to drive trains are merged. Also by reorganization of complex speed limits, we can understand easily when even the unusual situation and make a simple decision to prevent accidents. As a result, we can establish the system by doing subsequent actions quickly and accurately.

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